Protected underreamer



Aug.-19, 1930. J. GRANT PROTECTED UNDERREAMER Filed Mam'h 10, 1928 .172 en/0r. ,72/3/2 6221224 ing lowered to its Patented Aug. 19, 1930 v I 1.77am

PATENT w JOHN GRANT, or Los ANGELES, neurosis-Ia PROTECTED UNDER-REAMER Application-filed March 10,-1928.- Serial No. 260,713..

This invention has relation to expansive reamers or underreamers of the kind used for well drilling, and it relates most particularly to means and arrangements for protecting such a reamer against entry of muddy fluid, sand and silt. All expansive reamcrs and underrearners are more or less liable to be come filled and clogged with deposits of solid matter and in some cases they may become so clogged that they will not properly expand upon passing out of the bottom of the. easing. t is a general object of this invention to provide a protective means to prevent the reamer from becoming clogged while it is beplace of operation, and

so that it will infallibly expand when passes below the casing. When once expanded and put into operation, there is another protective means, and the water or fluid circulation is arranged and directed, to keep the reamer clean so that it will not be clogged against contraction when removal is desired.

I describe my invention as applied to a par-' tieular and specific type of reamer; but it will be readily understood. that the invention not necessarily restricted'to the particular reamer here set forth, but iscapable of application to other kinds and types of reamers having other particulars of design. In a reamer in which the body is slotted and the cutters or cutter-carriersmove longitudi nally in the slots for contraction and expansion, the end parts of the slots are necessarily left op'en-the cutters or cutter-carriers are necessarily shorter than the slots. It is through the open parts of these slots that the muddy fluid finds its me; or entry to the interior parts of the reamer; and my inventionv isfde'signedto close the open parts of such slots when the reamer is inits expanded position, as well as to close the open parts of the slots when the reamer is contracted; How this is done in the particular design here shown will be best understood from the following description, and from a consideration' of that description the invention itself wi'll best be apparent. For the purposes of detailed description of the present preferred embodiment "I refer to the accompanying drawings in which Figure 1 is a centrallongitudinal sectional view of a reamer equipped in accordance with my inventiornthis view showing the parts contracted position. i

*F'g'ure 2 is asimilar viewjshowing the parts expanded.

Figure 3 is fragmentary view-showing a modification of the invention.

Figure l is an enlarged cross section on line 4% of Figure 1.

The. typical reamer illustrated in the drawings has asubst'antially tubular body provided with a plurality of longitudinal slots 11, which I here show as innumber, although the numberof slots and therefore the number of cutters is largely a matter of choice. Inside this body there is a central mandrel. l2 vjoined at its pper end to the body at the screw-threaded joint 13 andde pending centrally in the bore ltof the bod as illustrated. The whole mandrel may be either made in onepiece' or its lower part maybe in the form of a, removable eaten? sion tube 15 which-extends to a point near the lower end of the body, the lowerend of tube 15 being close to thetool joint pin 16 of drilling bit 17, which is attached to the lower end of the body. I The cutter-actuating spring 18 surrounds the mandrel tube 15' and rests at its lower end upon a spring seat collar 19, which collar rests upon tool'joint pin 16 and surrounds the lower end of tube 15 to] steady the lower end of the mandrel against vibrationand thus to insure the mandrel against breakage. This compression spring 18 acts at its upper end on a cutter propeller 20,fwhich"is here shown as cylindric in form and slidably, but snugly, fitting the body bore M. In" its lowermost position this propeller 20 is'substantially below the lower ends of slots Hand in its upper position, as shown in Figure 2, its lower end is still somewhat below thelower. ends ofslots 11; so that in" all'its positions this'cylindric 'or piston like propeller 20' closes the lower part of bore 14,an d the smaller spring chainber bore 14?, against entry of fluid through the'slots' 11.- There is thus no entry op 11-. ing for muddy fluid into the, sprin chamber below-propeller 20 except thr'ougli the very lOO slight clearance spaces around propeller and between the propeller and the mandrel tube 15. And the propeller fits around the mandrel tube 15 as closely as is consistent with its sliding action on the tube, so that only a very slight clearance space is left at that point. 7

To provide for the washing out of any fine silt which may find its way into the spring chamber during operation, I provide that a part of the circulating water shall pass into.

and through the spring chamber during operation. It will be readily understood that when the reamer is in its contracted position, as shown in Figure 1, and is being lowered through the pipe to its place of operation, any small accumulation of fine silt or mud which may find its way into the spring chamher will not, to any great extent, prevent expansion of the spring or upward movement of propeller 20. The mud or silt accumulationthat might efiectively prevent upward movement of the propellers and cutters is that accumulation which may take place above the cutters; and prevention of that is provided for in the manner which I hereinafter explain. As far as the spring chamber is concerned, it is primarly necessary to prevent mud or silt accumulation in itwhen the parts are in the expanded position of Figure 2; and this is done first by the fact that propeller '20 closes the lower ends of slots 11, and second, by the fact that the water circulation through the expanded spring chamber constantly washes out any such accumulation as might otherwise take place through the small clearance spaces. The water circulation comes down through a longitudinal circulation passage in the mandrel and is extended on through. the tube 15. This circulation passes out of the tube atits lower end and thus goes to the circulation p ssage 26 of d ill bit 17 and may also, due to a somewhat loose fit of collar 19, pass from the lower end of tube 15 up into the bore 14. But the tube may also have perforations, such as shown at 27, to put circulating water directly into the bore from the tube. And discharge passages 28 are provided extending upwardly and outwardly, at the lower ends of the slots and under the cutters. so as to discharge a certain amount of circulation upwardly under the cutters. By this circula tion through the spring chamber, it and the spring arekept washed free of small accumulation of solid matter during the operation of the tool.

The cutting elements of the tool are here shown as comprising roller cutters 3O mounted in carriers 31. The mandrel 12 has an upper and comparatively large cylindric part 12' terminating at its lower end in a downwardly facing diagonal shoulder 12 In the collapsed position of the cutters, shown in Figures 1 and 3, the upper ends of the carsleeve r'ers 31 rest inwardly against a reduced por tion 12 of the mandrel directly below shoulder 12 lVhen the tool emerges below the casing and the cutters are allowed to expand, the action of spring 18 and propeller 20 is to, move the cutter carriers and cutters upwardly, the diagonal surface of 12 causing the upper ends of the carriers to move outwardly, and then the cutter carriers move directly upwardly to the position of Figure 2. In that position the upper ends of the carriers bear inwardly against the part 12 of the mandrel and the lower ends of thecarriers bear in wardly against the lower tapered part 12 of the mandrel. The carriers are provided at their side edges with wings 31, indicated in dotted lines in Figure 4, which overhang the edges of slots 11 to prevent the carriers from moving outwardly further than the expanded position of Figure 2.

The upper large cylindrie part 12 of the mandrel does not entirely fill the bore 14, but leaves an annular space betweeen itself and the wall of the bore. In this annular space, as shown in Figures 1, 2 and 4, I provide a sealing sleeve 35 which surrounds, and is longitudinally slidahle on, the cylindric portie-n 12 of the mandrel and fits snugly but slidably in bore 14. The length of this sleeve is such that, resting at its lower end upon the upper ends of the carriers 31, it entirely closes the, otherwise open upper ends of slots 11 when the parts are in the position of F igure 1. When the cutters slide upwardly the sleeve is moved upwardly above them into the position shown in Figure 2. lVhen the cutters are again pushed downwardly the 35 drops down with them and again :umes the position of Figure 1. Thus the sleeve 35 at all times closes the upper ends of slots 11 when the upper ends of those slots are not closed by the cutter carriers themselves.

In order to insure that the sleeve 35 shall not he accidentally moved upwardly when the cutters are held'in their lower positionsof Figure 1, I may provide a small latch which may conveniently be mounted in a slot 36 in the mandrel, the latch being pivoted at 37 and'having a latch head 38 at its upper end adapted to swing over the upper edge of: sleeve 35. The lower on d 39 of the latch is in such a position as to be en 'aged by the up- P3 per end of carrier 31 when that upper end is in the position of Figure 1. In this position the upper end of the carrier has been moved inwardly under the mandrel shoul der 12, and this inward movement of the upper end of the carrier, causing inward movement of the lower end 39 of the latch, causes the upper end of the latch to swing outwarc ly and over the upper edge of sleeve A small flat spring, shown at 40 in Figure 2, urges the latch head 38 back away from sleeve 35, so that when they upper end of car rier 31 moves upwardly and outwardly from the position of Figure 1, the lower end 39 of the latch may move outwardly and the upper .latch head 38 move inwardly to release the sleeve 35 and to allow it then to move upwith the cutters.

The protective sleeve 35 has been described as being located on the inside of body 10 and that is the locationywhich I prefer In that location the protective sleeve is not liable to 'be'disturb-ed orinjured by forcible contact with any exterior object. But; in a broad sense the sleeve may be otherwlse located and still perform its proper function.

- mountedon the outside of the body may be made of any suitable material. Situated in that position it may be subject to some considerable wear. And it may thus be made of a material calculated to resist such wear. On' the other hand it may be made of a relatively' soft material which will wear out or break up when the cutters move to their upper positions or when subjected to frictional contact with the side of the hole while the reamer is in operation. Thus. in the form of Figure 3 the sleeve may be made of a thin and soft sheet metal which, instead of sliding vertically on the body, will be torn or crumpled upwardly by the cutters when they are forced upwardly by the heavy spring 18.

Or the sleeve may be even made of sucha material as rubber'a rubber sleeve somewhat distended and placed in the position shown in Figure 3. Any such sleeve is protected from contact with the casing by the fact that the upper ends of the carriers project further outwardly than any other parts of the reamer and therefore take the frictional contact with the casing as the tool is being lowered. Thus in the particular form of reamer here shown the upper ends of carriers 31 are shown provided with renewable wear washers or members 50 which project out at least as far as the cutters 30 and thus I exclusively make contact with the casing.

I claim: 7 1. In a reamer of the character described, the combination of a longitudinally slotted tubular body, cutters movablelongitudinally in, the body slots and filling portions of the slot lengths from side to side, and a slot closing sleeve resting upon the upper ends of the cutters and adapted to close the otherwise open upper ends of the slots when the cutters are in position at the lower ends of the slots. 2. Ina reamer of the character described,

. the combination of a longitudinally slotted tubular body, cutters .nioiiable longitudinally in the body slots .anclqfill iing portions-ofthe slot lengt'zhstrom side to sides, and slot closing 7 members movable with'the cutters one, incon- ;tact with gone endoflthe cutters and-the other in; contaetfivithsthe otherendof; the cutters.

3;; 'Inxa neamer ofthe character described,

the combination of a. longitudinally slotted tubularibo'dy, cutters movable longituazlinally in} the-body slots andfilling portions ;of. the slot lengths from side toside.,an-d slot closing m members fitting theinternal bore of the body and I slielable therein {and contacting one with one end; ofth e, cutters and the other with :the other endof thecuttejrs.

In a reamer of the character the [combination :Ojll a longitudinally slotted tu ular e t.,-cut ers meuab e longitudinally r in the body slots and filling: portions of the slot lengths; from side .to side, a cutter, propeller, fitting 1 and ,slidable in (the internal bore of the bodyand'engaging the loweren-ds of the cutters; a spring urging said :propeller upwardly, and asilot, closing-sleeve resting upon theupper ends of the cutters andengaging the-body; closely at, the upper ends of .t'hes-lotsJ-o l I anear e the combination of a longitudinallyslotted tubularbody, cutters movable longitudinally r n the body-slots and fillingportions of the slotlengths from side to .side, acutter'pro peller fitting and slidablezin the-'inteltnailibole of the body and engaging the lower endsof t e utt ris,ra: spring. urg ng said propeller upwardly; al d ra slot closing sleeve wresting upon the upper ends'ofthe cutters and fitting slidably infthe body bore. 6 .-In a reamer. of the character described,

t ecom nat oniofia longitudinallyslotted tubularbody, cutters movable longitudinally thegbody slots andjfillingz portions of the slot lengths from side to; side, a cutter pitopellerfit-ting and slidablein the internal bore of, the, body and eng ging the lower ends of of the characte1- described,

the cutters, a spring urging said propeller upwardl nd aslot closing sleeve resting upon the upper endsv of :thecutters and engag ng the body closely, around. the upper ends of. the slots,1said ,spring bei-nghoused within thePl erpart-of thebod-y bore below he propell and. means :for passing-cireu1at-- iug fluidthroug r hatpart oirthe body bore below the propeller. 1 Q

I 7 Ii -are r erof the character described,- he comhiuationof a longitudinall slotted tubular body, cutters movableiler gitudinirlly in-thebodyfslomend a slot closing sleeve resting upon the upper ends of the cutters and adapted to close the otherwise open up u;

per ends of the slots when the cutters are in position at the lowerends of the slots, and a cutter actuated latch adapted to hold the slot closing sleeve in its lowermost position.

8. In a'reamer of the character described,

asubstantially tubular body having longitudinalslots in its wall, cutters mounted in the said slots and movable longitudinally therein, a central mandrel extending verti- 5 cally through the longitudinal bore of the body, said mandrel and cutter being formed 7 so that upward movement of the cutters in the slots causes their outward expansive movement, a cutter propeller vertically mov- 10 able in the lower part ofthe body bore below the cutters, said propeller slidably fitting the body bore so as to'close the lower ends of'the body slots when moved upwardly, a spring in the body bore below the'propeller and urging it upwardly, a slot closing sleeve surrounding the upper part of the mandrel and slidably fitting in the upper part of the body bore above the cutters and closingthe upper ends of the body slots when the cutters are in their lower positions, said sleeve being movable upwardly with the cutters as they move upwardly in the slots.

9. In a reamer of the character described, a substantially tubular body having longitudinal slots in its wall, cutters mounted in the said slots and movable longitudinally therein, a central mandrel extending vertically through the longitudinal bore of the body, said'mandrel and cutter being formed so that upward movement of the cutters in the slots causes their outward expansive movement, a cutter propeller vertically movable in the lower part of the body bore below, the cutters,'said propeller slidably fitting 5 the body bore so as to close the lower ends of the body'slots when moved upwardly, a spring in the'body bore below the propeller and urging it upwardly, a slot closing sleeve surroundingjthe upper part of the mandrel 40 and slidably fitting in the upper part of the body bore above'the cutters and closing the upper ends of the body slots when the cutters are'in their lower positions, said sleeve being movable upwardly with the cutters as they move upwardly in the slots, the mandrel extending downwardly through the body to a point near its lower end and below the cutter propeller, the mandrel having a fluid circulation passage with an outlet into the body bore'below the propeller, and a body having discharge passages leading from the bore below the propeller for effeotu'ating circulation through the bore below the propeller and around the propeller actuating spring. In'witness that I claim the foregoing I have hereunto subscribed my name this 4th day of February, 1928. I

: 4 JOHN GRANT. 

